Hand sanitizing products, including those that are alcohol-based, are known in the art. The use of alcohol-based hand sanitizing products, in particular, continues to grow, both within the United States and internationally. Alcohol-based sanitizers can be found in hospitals and other healthcare environments, the workplace, and in everyday home use. These products are considered especially useful when microbial contamination is a concern, particular in high risk areas of hospitals and prior to surgical procedures.
Some examples of high alcohol content sanitizers include U.S. Pat. No. 6,723,689, which describes an emollient antimicrobial composition comprising high alcohol content (60-95 wt. %), preservatives, a cationic cellulose polymer thickening agent, and silicone-based moisturizers and emollients, useful as a hand healthcare preparation or a pre-surgical scrub; U.S. Pat. Nos. 6,610,315; 6,562,360; 6,352,701 and 5,951,993, which describe alcohol compositions useful as pre-surgical scrub replacements or as a lotion or other hand preparation, comprising alcohol and a non-polymeric thickener system that includes mixtures of at least two emulsifiers; and U.S. Pat. No. 6,423,239, which describes a gel product for use as a skin sanitizer having a higher alcohol content and comprising, humectants, silicones as detackifying agents, moisturizers, and thickeners.
Alcohol and alcohol gels in which alcohol levels exceed about 50% have the most pronounced immediate antimicrobial effects; however, they lack persistent antimicrobial properties, i.e., residual activity or effect. Although alcohol may kill microbes on contact, upon drying, there is no means for killing or controlling microbial growth. As such, sanitizers using alcohol alone are often less effective over time. Hence, some alcohol-based compositions utilize additional antimicrobial compounds, which may themselves cause skin irritation and sensitization.
In addition, many alcohol-based products comprise thickening agents or emollients that increase the viscosity of the composition, in order to lower the alcohol evaporation rate and increase the exposure time that the alcohol is present on the skin. These thickened compositions often result in a less than optimal aesthetic skin feel in use or upon rinsing. Prolonged contact of high alcohol content may also dry and irritate the skin, and thickeners may trap dead skin and bacteria on the surface of the skin.
Alcohol-based antimicrobial compositions that provide prolonged and enhanced activity against various microorganisms without the need for additional antimicrobial agents have been described in the art. For example, U.S. Pat. Nos. 7,268,165 B2 and 7,985,773 82 (both to Greten et al., STERIS Corporation) describe antimicrobial compositions comprising a synergistic combination of a simple aliphatic alcohol and an activity enhancing substance (an aromatic alcohol or cationic substrate binding compound) that provides unexpected and persistent activity against a broad range of microorganisms, while, at the same time, moisturizing the skin. While additional antimicrobials may be added as an option, they are not required in order to provide enhanced and prolonged antimicrobial effect. The Greten et al. compositions are stated to be useful as hand sanitizers or pre-surgical scrubs, but are not foaming compositions.
Foaming alcohol sanitizers have been commercially available for many years, especially in healthcare settings. Traditionally, most foaming alcohol sanitizers used propellant-based, i.e., aerosol, technologies to create and stabilize foam, and these products are still widely used in this market. However, due to recent concerns about disposal of propellant systems, environmental sustainability, various safety issues, and regulatory scrutiny, non-aerosol, alcohol-based products have recently found their way into the market as replacements for aerosol products.
Most non-aerosol, alcohol-based foaming hand sanitizers utilize either fluorosurfactant or linear silicone surfactant chemistries to lower the surface tension of the alcohol system to a level that creates foam in an alcohol-rich environment. Most of these products have poor moisturization and aesthetic properties, when dispensed through an appropriate dispenser (mechanical). By way of example, U.S. Pat. No. 7,723,279 describes a foaming non-aerosol, alcohol-based composition comprising polymeric fluorosurfactants as foaming agents; and U.S. Pat. No. 7,683,018 describes a foaming non-aerosol, alcohol-based composition comprising anionic phosphate fluorosurfactants as the primary foaming agent. Other compositions are commercially available that utilize fluorinated surface active agents.
Other non-aerosol, alcohol-based compositions utilize silicone-based compounds either as the sole foaming surfactant or in conjunction with fluorosurfactants or other surfactants. Some examples include: U.S. Pat. No. 8,053,399, which discloses a foaming composition containing very little water that comprises the dimethicone copolyols PEG-10 dimethicone, PEG-12 dimethicone, or mixtures thereof; U.S. Pat. No. 7,670,615 (polysiloxane-polyether copolymers, such as, for example, a bis PEG-PPG-20/20 dimethicone); U.S. Pat. No. 7,651,990 (dimethicones and dimethicone copolyals with PEO and PPO side chains); U.S. Pat. No. 7,186,416 (polyoxyethylene ethers, esters, fatty acids, sulfated acids, sulfosuccinates, polysiloxane, sorbitan fatty acid esters, polyoxamers, and the like); and U.S. Pat. No. 7,842,725 (linear PEG 8-PEG-12 dimethicones having foam heights greater than 20 mm). Dimethicone copolymers, such as PEG/PPG 18/18, 17/18, 4112, 35/65, among others, are disclosed in U.S. Publication No. 2009/0326076; and derivatized dimethicones, such as PEG-8-12 dimethicones coupled with foam strengthening agents are disclosed in U.S. Publication No. 2009/0098067.
There are disadvantages to the currently available non-aerosol alcohol foam products that are currently in the market. First, there exists a general negative perception with regard to fluorosurfactants and their persistence in the environment and overall toxicity profile. Based on this perception, some have used traditional linear silicone surfactants to achieve foam creation in alcohol systems. Though not as effective as fluorosurfactants from a foam-generation standpoint, silicone surfactants are capable of producing a moderate amount of stable foam, especially when used at fairly high concentrations (e.g., 3%-5%).
Secondly, non-aerosol alcohol foam systems are very sensitive to excipient ingredients that could normally be used to enhance other attributes, specifically moisturization and overall feel. Alcohol sanitizers, due to the high level of alcohol required for acceptable microbial efficacy, can be inherently drying to the skin. Standard alcohol gels or liquids often contain water-insoluble, but alcohol soluble (or miscible) ingredients (such as occlusive agents) to improve overall moisturization benefits. However, due to the complex foam structure of alcohol-water mixtures, these ingredients often have a very significant negative impact on foam generation, quality and stability. Hence, ingredient selection may be limited.
The potential limitation for ingredient selection can also impact the microbial efficacy of the system. Though high levels of alcohol have good immediate efficacy against a broad range of microorganisms, due to its volatile nature, little prolonged microbial activity can be achieved without the addition of ingredients that either help retard the evaporation rate and/or bind to the skin. However, most ingredients traditionally used for this (e.g., cellulosic thickeners, high molecular weight occlusive agents) cannot be used in non-aerosol foam products.
As is evident from the foregoing, many non-aerosol alcohol foam systems have poor moisturization properties and/or limited microbial efficacy. While U.S. Pat. Nos. 7,268,165 and 7,985,773 to Greten et al. describe compositions that have enhanced and prolonged microbial efficacy and excellent moisturization properties, the compositions also contain thickeners that are not conducive to non-aerosol foam production.
In a healthcare environment, the CDC Guidelines for Hand Hygiene in Health Care Settings include recommendations for increased use of alcohol-based sanitizing products and, at the same time, express significant concern with skin health issues resulting from their use. Alcohol-based sanitizing products are often used on hands that do not have a visible organic load, however, many currently available products are negatively impacted by both the presence of any organic load, even that not clearly visible, and dilution. In order to leverage the CDC guidelines properly and provide a product that also has enhanced moisturization capabilities that are equivalent or superior to current alcohol-based foam sanitizers, an alcohol based foam sanitizer having efficacy and enhanced skin care properties in the presence of organic load and on repeated application is needed.
Further, the Tentative Final Monograph for Health-Care Antiseptic Drug Products sets forth the FDA criteria necessary to make the claim of “Healthcare Personnel Handwash.” It is believed that when the tentative monograph issues as a final version, the criteria outlined in the tentative version will remain. For example, the Healthcare Personnel Handwash Test outlined in the tentative monograph establishes criteria that require a 2 log (base 10) reduction in bacteria after the first application and a 3 log reduction in bacteria after the tenth application. Because of the high inoculums and organic load present in the required methodology, not all alcohol-based sanitizing products can meet these criteria, especially after the tenth application and in fact, may actually demonstrate a decrease in log reduction when compared to the first application. Indeed, alcohol gel products used alone were not considered as good, from both an overall microorganism reduction profile and skin irritation potential, as a combination of alcohol gel with either an antimicrobial or a plain lotion soap. Paulson at al, Am. J. Infect Control 1999; 27(4): 332-38. Combination regimens may, therefore, be preferred to achieve persistent antimicrobial properties that are required by FDA criteria.
There is a need, therefore, for non-aerosol, alcohol-based hand sanitizing foam products having enhanced and prolonged antimicrobial activity, tolerance to organic load and dilution, excellent residual activity, skin moisturization and aesthetic skin feel properties, while at the same time meeting all of the CDC and FDA requirements.
A novel non-aerosol alcohol foam sanitizer has been discovered that resolves the disadvantages of current alcohol-based foam sanitizers and that will meet and exceed the criteria for a Healthcare Personnel Handwash claim. The invention is a non-aerosol alcohol foam hand sanitizer that comprises a novel silicone-dimer reaction product which, in combination with known components, resolves several issues encountered with alcohol-based sanitizing products in the past.
The inventive composition provides both the necessary surface tension reduction to allow a high alcohol system to foam without the use of propellants and aids in improving moisturization and aesthetic skin feel properties of the final product. The system contains certain ingredients previously known to enhance and prolong antimicrobial efficacy in combination with moisturizing components, but also contains novel components, not used heretofore, that provide unexpectedly high-quality, stable foam and excellent moisturizing and skin feel properties over current commercially available products.
Specifically, the inventive composition contains a high level of an aliphatic alcohol, a silicone based surfactant system comprising a novel silicone dimer reaction product, i.e., bis-PEG-10 dimethicone/dimer dilinoleate, PEG-17 dimethicone, or mixtures of both; activity enhancing substances, including an aromatic alcohol, a cationic substrate binding component, or mixtures thereof; a polyquaternium component; a blend of humectant ingredients; a cationic surfactant(s); and water-soluble emollient ingredients, all in an aqueous base. The composition is efficacious against a broad range of microorganisms, including gram-negative organisms. Importantly, the composition meets the Healthcare Personnel Flandwash guidelines at both one and ten applications, based on the criteria set forth in the Tentative Final Monograph for Health-Care Antiseptic Drug Products (1994, 21 CFR Parts 333 and 369).
The final inventive corn positions have unexpectedly superior moisturization and aesthetic feel characteristics, making it more likely that they will be used multiple times throughout the course of the day. The aesthetics of the inventive composition are such that the rub-in time, residue and foam properties are similar to current commercially available non-aerosol alcohol-based foam products, but with superior after-feel properties.
It is an object of the invention to provide a non-aerosol, foaming alcohol-based hand sanitizer product, having excellent moisturization and aesthetic skin-feel properties, while still producing a large amount of quality foam that is stable even in the presence of high amounts of alcohol.
It is yet another object of the invention to provide a non-aerosol, foaming alcohol-based hand sanitizer product having enhanced and prolonged antimicrobial activity against a broad range of microorganisms, including gram negative organisms, that is, at minimum, equivalent, but in many instances superior, to the antimicrobial activity of currently available non-aerosol, foaming alcohol-based hand sanitizers.
It is a further object of the invention to provide a non-aerosol, foaming alcohol-based hand sanitizer product that has superior tolerance for organic load and dilution, even with repeated applications, and excellent residual activity as compared to currently marketed non-aerosol, foaming alcohol-based hand sanitizers.
It is a further object of the invention to provide a non-aerosol, foaming alcohol-based hand sanitizer that is environmentally friendly, free of fluorosurfactants and that meets CDC guidelines and FDA criteria for hand sanitizing compositions.